On Windows 7, I have an application that can't run in 64 bit. How do I invoke
wow64 manually? Compatibility mode does not work, nor does pasting it into
C:/Program Files (x86)/.
You cannot. If the .exe file is marked as "x64", Windows will run it in 64-bit mode. If the .exe is marked as "x32", it will be run in 32-bit mode using wow64. Having "an application that can't run in 64-bit" doesn't make much sense, as 32-bit programs are never run directly in 64-bit mode.
A more specific problem description than just "can't run" would be helpful.